A review of the T2 segment of the brachial plexus.

Although the complex architecture of the brachial plexus (BP) has been described for decades, recent literature still aims to elucidate the variation in nerve root contributions to the BP. Understanding this variability in the nerve morphology of the BP may assist physicians and surgeons in the diagnosis and management of certain clinical conditions that involve the BP, either directly or indirectly due to its close association with neighbouring structures. In this article, we review the current anatomical knowledge of the BP, focusing especially on its T2 contribution, and discuss the causes and consequences of some relevant BP pathologies.